Therefore, it is convenient to introduce two separated spaces: \(\mathbb {V}\)  as the space of all feasible flux configuration \({v}\)  that a particular cell metabolism can display, and \(\bar{\mathbb {V}}\)  as the space of all feasible average flux configurations \(\bar{{v}}\)  compatible with the measured observables of the culture.
If the nature of all constraints acting over the system is linear, as it is in our case, both \(\mathbb {V}\)  and \(\bar{\mathbb {V}}\)  are high-dimensional convex polytopes [1]}.
The convexity of \(\mathbb {V}\)  implies that \(\bar{\mathbb {V}}\subseteq \mathbb {V}\) .
That is, any observable feasible flux configuration \(\bar{{v}}\)  at the population level, is a feasible flux configuration for single cells \({v}\) , and no unfeasible single-cell flux configuration can be observed at the population level.
